Examine source code of CodeChef Copy TC

{
  "manifest_version": 2,
  "name": "CodeChef Copy TC",
  "version": "1.0",
  "description": "Adds a copy button besides test case.",
  "icons": {
    "48": "icons/logo_48.png",
    "96": "icons/logo_96.png"
  },
  "content_scripts": [
    {
      "matches": [
        "https://www.codechef.com/*problems/*"
      ],
      "js": [
        "testcase.js"
      ]
    }
  ]
}